As a hitherto known illuminating device, particularly, an outdoor illuminating device used for a street light or the like, a high-luminance light source is used, such as a mercury vapor lamp, a high-pressure sodium vapor lamp or a metal halide lamp, which is a high-luminance discharge lamp, and is widely installed around facilities such as a road, a parking lot or the like. Also, as an indoor illuminating device, a fluorescent lamp, an incandescent lamp or the like is widely used for an interior lamp.
Patent Document 1: JP-A-2003-100111